Using Control Messages (IIS 6.0)
Control messages are specially formatted newsgroup messages that can create newsgroups, delete newsgroups, and delete posts. You can enable or disable control messages for newsgroups and for newsfeeds. If you enable control messages, then they are enabled for every user. If you want to restrict access to control messages to administrators only, then set appropriate ACLs for the control groups and enable either Basic authentication or Integrated Windows authentication.
In IIS Manager, use the Settings tab in the NNTP virtual server properties dialog box to enable or disable control messages for newsgroups. Use the Rfeed.vbs command-line script to enable or disable control messages for newsfeeds. Control messages are disabled by default in IIS 6.0. However, if you have upgraded from the Microsoft® Windows® 2000 operating system and you enabled control messages in that operating system, control messages are enabled in IIS 6.0.
Generating Control Messages
Control messages are generated automatically by NNTP client software, NNTP servers, and special utility programs. You can also generate control messages manually by connecting to the NNTP server using Telnet and entering the control messages directly.
The NNTP service accepts the following basic control messages:
Cancel: Deletes a specified article.
Newgroup: Creates a newsgroup.
Rmgroup: Deletes an existing newsgroup.
The Cancel control message is generated by client programs. The Newgroup and Rmgroup messages are typically generated by NNTP servers.
Control messages look like other newsgroup messages, but control messages have the following headers:
From: The name of the user or service from which this message originated.
Subject: A description of the subject.
Newsgroups: The name of the newsgroup affected by the control message, such as control.cancel|newgroup|rmgroup or any other valid newsgroup.
Approved: The user or administrator who created the message. If the newsgroup is moderated, the name of the moderator must appear. If the group is not moderated, any name can be used.
Control: The control header. Control messages must contain one of the following control headers:
| • | Newgroup <name of new group>. Creates a new group, for example, newgroup Test.One. |
| • | Rmgroup <name of group to delete>. Deletes an existing newsgroup, for example, rmgroup Test.One. |
| • | cancel <MessageID>. Deletes the message that is referenced by the message ID, for example, cancel <BMO2mVOECHA.2772@server.domain.microsoft.com>. |
A blank line separates the headers from the message body. The message body can contain any text, or it can be blank. The following appears at the end of the control message:
{CRLF}.{CRLF}
Restricting Access to Control Messages
When the NNTP service receives Cancel, Newgroup, and Rmgroup control messages, it posts them into the following newsgroups, respectively: control.cancel, control.newgroup, and control.rmgroup. These newsgroups are created automatically. Control messages are sent to the control newsgroups regardless of where they were originally posted. The NNTP service also automatically creates a control virtual directory.
Restrict access to control messages to prevent unauthorized users from changing your newsgroups or deleting messages. You can restrict access by configuring the control newsgroups as moderated newsgroups or by restricting access to a limited group of users. For more information about moderating and restricting access, see Moderating Newsgroups and Configuring NNTP Virtual Server Properties.
In addition, any ACLs that you have in place for your existing newsgroups apply to control messages. For example, if you have a newsgroup named Microsoft.Software and you have secured the \Inetpub\Nntpfile\Root\Microsoft\Software directory with ACLs that restrict anonymous users from creating subfolders, then when an anonymous user posts a newsgroup control message in Microsoft.Software, the control message is not processed.